Unfortunately, I don’t think so. There were some changes made to the shortcode API recently, which developers who paid attention during the month-long public beta of WordPress 4.4 noticed and fixed.
If your theme’s developer isn’t helping, perhaps it’s time for a new theme? It’s not too unreasonable to expect more things to break down the line.
Though every effort is made to maintain backwards compatibility, the WordPress developers do count on the few plugin/theme developers out there to test and fix their few products in the public betas (as opposed to the few volunteers WordPress developers having to test hundreds of thousands of plugins+themes themselves).
So, if you find yourself using a product from a developer who didn’t test/fix during the month-long public beta period, who still hasn’t tested/fixed in the month since 4.4’s release, and who won’t respond to your support requests, it’s probably time to move on to a different theme.